Stitching machine



April 20, 1943. w. R. PABICH ET AL 2,317,298 STITCHING MACHINE Filed July 22, 1940 4 Sheets-Sheet l fiuenZonsx- Q) EPabc'c/v. BY Hererllfonf.

wqehm April 20, 1943. w. R. PABICH ETAL STITCHING MACHINE Filed July 22, 1940 4 Sheets-Sheet 2 flereri Tel/for I W. R. PABICH ETAL STITCHING MACHINE Filed July 22, 1940 4 Sheets-Sheet 3 Ink/67122719:-

,flere'rtfefiom QQLMK APTil 1943- w. R. PABICH ETAL I 2,317,298

STITCHING MACHINE Filed July' 22, 1940 4 Shets-Sheet 4 I w I 722/87Zib713- flerbefelfo' rJ.

Patented Apr. 20, 1943 STITCHIN G MACHINE Walter Pabich and Herbert Tellfors, Chicago, Ill., assignors, by direct and mesne assignments, to Harris-Seybold-Potter Company, Cleveland, Ohio, a corporation of Delaware Application July 22, 1940,, Serial No. 346,836

7 Claims.

The present invention relates generally to a wire stitching or stapling machine, but more particularly to a semi-automatic type tie stitching machine in which a single wire stitching head of the conventional type and a single reel of wire is employed to effect a tie stitch of the form in which the first two and last two staples in each article to be stitched such as a box blank are placed in close proximity with respect to each other while the intervening staples are spaced apart at normal pre-determined intervals.

One of the objects of the invention is to provide a novel and improved tie stitching mechanism in which the conventional stitcher head may be employed so as to automatically effect a differential spacing between certain of the staples in each box blank.

A further object of the invention is to provide a novel and improved stitching mechanism in which a single conventional type stitcher head may be employed to secure a difierential spacing or interval between the stitches or staples in the box blanks and also having means associated therewith whereby the spacing between the staples may be adjusted so that any pre-determined number of staples may be inserted in the box blank.

A still further object of the invention is to provide a novel and improved stitching mechanism in which a single conventional type stitcher head may be employed in combination with associated mechanism so as to effect either a seam of uniformly spaced stitches or one in which the two stitches at each end of the seam are spaced more closely than the rest.

These and other objects are accomplished by providing a construction and an arrangementof the various parts in the manner hereinafter described and particularly pointed out in the appended claims.

Referring to the drawings:

Fig. 1 is a fragmentary top plan view of our improved stitching machine with the stitcher head shown at an angle of forty-five degrees with respect to the main drive shaft;

7 Fig. 2 is a top plan view of a box blank illustratlng one form-of the tie stitch in which the staples are arranged at a 45 angle;

Fig. 3 is a similar view of a box blank showing another form of the stitch in which the staples are at right angles to the direction of travel of the box blanks;

Fig. 4 is a similar view of a box blank showing a third form of tie stitch in which the staples are placed parallel to the direction of travel of i of the. main frame.

Fig. 7 is a fragmentary front elevational view of our improved stitching mechanism with the stitcher head removed therefrom;

Fig. 8 is a perspective view of our improved tie stitching machine with the, stitcher head shown at right, angles to the main drive shaft;

Fig. 9 is a cross. sectional view taken on the line 9.9, in Fig, 1 and 1 Fig. 101s afra mentary view showin parts of the. trip control for the tie stitch mechanism.

In illustrating our, invention we have shown the. same as comprising a main frame or standard I 0 which has the usual horizontal projecting arm. ll. Secured to the frame, l0. below the arm I I is, the usual work table. l2. J ournaledin suitable bearings in the horizontal arm II is a main drive shaft l3. Loosely mounted on the rear end of the shaft I3 is a drive pulley M, The pulley i4 is. operatively driven byv an electric motor (not shown). Positioned between the pulley l4, and the main shaft [3 is a clutch mechanism generally indicated by the reference character l5. This clutch I5, is of any well known form and may be manually or foot controlled, or may be automatically. tripped by means located in the path of. the articles to be stitched as. will hereinafter be more fully described. Secured tothe driven pulley M is a sprocket wheel [6,. Mounted in the bearing bracket l I. secured to the mainframe It is a stub. shaft l8. Secured to the outer end, of the stub. shaft I8 is .a sprocket wheel I9, The sprocket wheel Ill-is geared to the sprocket wheel LG by means of a chain 20. Secured to the shaft l8. adjacent the sprocket wheel I9 is a gear 21. J ournaled in the bracket I1. above the stub shaft 18 is a longitudinally extending shaft 22.. The shaft 22 is driven bya gear 23 which in turn meshes with the gear 2|. The other end of he shaft 22 is provided with two. continuously driven spaced apart kick-out rollers, 24., which are 1ocatedbelow, but protrude slightly above the table as clearly disclosed in Figs. '7 and 8 of the draw lugs. .The, table [2 is, supported on and above a horizontally disposed frame-member 25 which has its inner ends secured to the vertical standard I Q The outer end of the shaft 22 is; journaled in a bearing 26 of a bearing bracket 21. Spaced rearwardly from the bearing 26 and formed integrally with the bracket 27 is a second bearing 28 in which an intermittently driven shaft 23 is journaled. Secured to the shaft 29 and in alignment with the continuously driven rolls, 24 are horizontally spaced apart intermittent feed or conveyor rolls 3c. The inner end of the intermittently driven shaft 29 is pro vided with a gear 3|, which in turn, is op eratively driven by a gear 32 secured to a shaft 3.3. The outer end of the shaft 33, is journaled in the bearing bracket [1. The intermittent motion is transmitted to the shaft 33 from the main drive shaft 35.

of flexible or universal joint 31 is a flexible shaft shaft l3 by the mechanism that will hereinafter be more fully described. Meshing with the gear 3| is a gear 34 Which in turn, is secured to a stub Connected to the shaft 35 by means 31. The outer end of the shaft 37' is connected by means of a flexible joint 38 to a shaft 39. shaft 39 has its opposite ends journaled in spaced apart arms 46 which in turn, have their intermediate portions pivoted on pins 4|. The pins 4! are secured to fulcrum brackets 42. The fulcrum brackets 42 are secured to the oscillating shaft 43. The shaft 43 is journaled in spaced apart bearings 44 of a bearing bracket 45 which is secured to the horizontal arm I I of the main frame. Positioned in vertical alignment with theintermittent conveyor rollers 39 are complementary spaced apart upper feed rollers 46 which are secured to the intermittently driven shaft 39. The rollers '45 are yield-ingly pressed into engagement with the box blanks passing thereunder by means of springs 41. Journaled in the rear end of the bearing brackets 42' is a shaft 48. Located in vertical alignment with the continuously driven discharge or kick-out rollers 24 and secured to the shaft 48 are idle rollers 49. The outer end of the shaft 43 is journaled in a bearing bracket 50 which in turn is secured to the main frame member III in any well known manner. Secured to the shaft 43 adjacent the bearing 50is a rocker arm 5|. The free end of the rocker arm 5! is provided with a roller 52 which is located in the path of and adapted to be engaged by an eccentric cam 53 which in turn is secured to the main drive shaft I 3. I

From the above descriptionit will be obvious thatwhen the article to be stiitched such as a box blank is, inserted so as to engage the trip hereinafter described, said trip will automatically engage the clutch which operates the main drive shaft I 3 to revolve the cam 53. The cam 53 during its cycle of operation, will then engage the roller 52, thereby rocking the shaft 43 and its associated brackets 42 and arms 40 so as to lower the intermittently actuated feed rolls 46 and The thereby press the box blank between these rollers 7 and the lower intermittently driven feed rollers 30. Secured to the inner end of the shaft 43 is a clutch control lever 54 which is adapted to keep the clutch in driving operation with the main drive shaft when the intermittently acting feed rollers are feeding the box blanks to the machine for spacing the staples} Located in an opening in the table l2 and in the path of the incoming box blank is a vertically movable clutch throw-out trip control member 55 which has its lower end secured to a horizontally movable bar, 56; The bar 56 is pivotally connected to parallel links or arms 51 and 58. The link58 is secured to a shaft 59. The shaft 59 is journaled in a bearing formedin the supplemental: frame member 66 which in turn is secured to the frame member 25.- The link 51 is pivoted on a pin 6| mounted in the outer endof the bracket 60. Secured to the inner end of the shaft 59 is an arm 62, the free end of which is connected to the lower end of a pitman 63. The upper end of the pitman 63' is pivotally connected to the free end of an arm 64. The arm 64 is securedto a stub shaft 65 which is journaled in a bearing bracket 66 which in turn is secured to the, main frame o'rstandard H. Secured to the inner end of the stub shaft 65 is a. depending arm 61. The free end of the arm 61, is connected to a slotted link 68. Pivoted to a pin 69 mounted From the above description it will be seen that v V as the box blank is moved into the position beneath the stitching mechanism it engages a trip clutch hereinafter described, so as to actuate the clutch into engagement with the main drive shaft. In this connection it will be noted that the incoming box blank will depress and hold the throw-out trip 55 in its lower position. At this instant the roller 14 on the rocker arm 5! will ride downwardly along the forward edge of the clutch locking lever 10 so that when the cam 53 actuates the cam roller 52 and rocker arm 5 l' downwardly, the roller 14 will engage the notch 13 of the clutch lock-out lever 10 so as to maintain the intermittently actuated feed rolls 46 and 30 in engagement with the box blank located therebe tween. In this connection it will also be noted that as the rear end of the box blank passes the trip 55, the mass or weight of pitman 63 will return the strip 55 to its upper position and will swing the clutch locking lever 10 outwardly to disengage the notch 13 from the roller 14, thereby permitting the rocking arm together with the intermittent feed rolls to separate, at the same time releasing the lever 54 to actuate the clutch mechanism and disengage it from the main drive shaft l3 of the stitcher head. In this connection it will also be noted that as the rocker arm 5| is raised, by spring 5i'- and arm 52 the idle rollers 49 will be depressed toward the rear continuously driven kick-out rollers 24 to discharge the box blank rearwardly of the machine. A conven-' tional form of braking mechanism generally in dicated by the reference character 33 is provided for stopping the intermittently driven roller at the conclusion of each movement. I

The mechanism hereinbefore described cone stitutes essentially the conventional operative parts which are essential to the function and operation of our improved tie stitching machine. One of the essential features of this novel improvement includes the employment of a single conventional stitcher head, a single wire reel and associated adjusting mechanism which permits the stapling of box blanks so as to effect automatically the insertion of staples at different predetermined intervals, thereby permitting "a tie stitch at both ends of the box blank. The tie stitch in the present instance permits the stapling of the two successive staples at the beginning and the end of the box blank in relatively blanks where the staples proper are 'angularly disposed with respect to the direction of travel of the box blanks or are arranged parallel to the direction of travel of the box blanks as shown in Fig. 4 of the drawings.

Our improved type of stitching mechanism contemplates the employment of a conventional type stitcherhead, in this. case. generally. indicated by the reference character I0. The stitcher head 16 in this instance, as shown in Fig. 1 of the drawings, is located at an angle of substantially 45 with respect to the main drive shaft I3, but it is quite obvious that the same may be placed at right angles thereto as shown at IS in Fig. 8 of the drawings, or at any angle with respect to the main drive shaft. In order to drive the stitching head mechanism of the conventional construction from the main drive shaft I3, miter gears TI and I8 as shown in Fig. 1 of the drawings, are employed. The staple forming and driving mechanism and operative parts associated with the stitcher head are conventional in every respect and for that reason it is believed that a further detailed description is unnecessary. Secured to the rear end of the main drive shaft I3 is a driven disc 70. Attached to the disc I9 is a cam disc 80. The disc 79 is provided with a radially disposed T slot SI. Adjustably mounted in the T slot BI is a block 82. Mounted in a radiall disposed threaded bore 03 in the block 82 is a threaded bolt 84. The bolt 84 is provided with a shoulder or annular collar 85 formed integrally therewith and spaced from the head of the bolt so as to form a shoulder to be engaged by transverse plate 06 which in turn is secured to the disc I9 in any well known manner. Protruding outwardly from the block 82 is a pin or stud 81. on which is pivoted the upper end of a pitman 8B. The lower end of the pitman 88 is connected through the medium of a pin bolt 89 which in turn is secured to a ratchet pawl arm 90. Secured to. the shaft 33 adjacent its inner end is a ratchet wheel M, which in turn is provided with a hub 92. The pawl arm Bil is iournaled on the hub 92 of the ratchet wheel. (See Fig. 6 of the drawings.) Pivoted on a pin or bolt 03 on the free end of the is a ratchet pawl 94. Secured to the bracket. I! in any well known manner is a bracket 95. Formed integrally with the bracket 95 is an angularly disposed block 96. The block 90 is provided with a rectangularly shaped and angularly disposed slot 9'! in which a bar 98 is slidably mounted. Secured to the upper end of the post or bar 98 by means of machine screws 99 is a ratchet shield I00. The shield I00 has a longitudinally extending slot I0! which is adapted to embrace the shaft 33 so as to permit the shield to be lowered or raised with respect to the ratchet wheel 0! in the manner hereinafter described. Ihe shield I90 is provided with a sector or fan-like section M12. The sector-like section I02 of the shield I00 is of an arcuate shape whose periphery in raised position projects slightly above the periphery of the teeth of the ratchet wheel so as to be in a position to engage a laterally projecting portion I03 formed on the free end of the pawl 94 to hold the pawl out of engagement with the ratchet teeth of the ratchet wheel ill during certain operations of our tie stitching machine. In this connection it will be noted that if th operator is desirous of efiecting a normal stitching operation and eliminating thetie stitch, the same may be accomplished by locking the shield 100 in any manner in its lowermost position so that full stroke of the pitman 85 may be employed there by permitting the pawl to engage the ratchet wheel teeth during its full stroke. In this connection it will also be noted that a variation in the interval or space between the adjacent stitches may be accomplished by adjusting the bolt 8Q so as to vary: the. position of the pin. 81- from the center of? the drive shaft. or disc I9. thereby permitting the normal interval between the staples to be set at any: lore-determined distance.

In order to effect. the tie stitch or two stitches at closer. intervals. at: the beginning and the end of each box blank and also provide means for varying the. intervals between a, tie stitch and an adjacent regular stitch, we have provided a supplemental' or an adjustable shield extension I04. The shield extension I04 has. an. arcuate portion co-extensive with that of. the shield I00 and is provided with a. circular opening I05 which engages an annular flange or hub I06 formed integ-rally with the shield I00. The shield I00 is provided with an arcuate slot I07! through which a bolt, Inc is adapted to extend. The bolt I08 has its lower threaded portion adapted to engage a threaded aperture I I9. located in the adjustable shield I04. From the above it will be quite obvious that the shield extension I04 may be adjusted or rotated with respect to the shield I00 and fastened in various. positions of adjustment with respect thereto by tightening the bolt I08. It will. be noted that the amount of the movement of the ratchet wheel illv imparted by the pawl El i is determined by the position of the shield I04 with respect to the shield I00. In other words, the effective stroke of the pitman 80 imparted to the pawl 94' is controlled by the adjustment of the shield extension IIM' with respect to the shield I 00 so that if the operator is desirous of adjusting. or changing the intervals between the first two and the last two staples inserted in a box blank, the same may be effected by adjusting the shield extension I04 with respect to the main shield I00. It is quite obvious. from the above that. when the ratchet shields I00 and I04 are held in their downward position, the normal full stroke of the pawl. 94 is imparted to the ratchet wheel which in turn imparts its motion to the intermittently driven upper and lower feed rolls 46. and 30: for properly spacing the intermediate staples at uniform intervals, dependent upon the distance at which the pitman pin 8'? is set with respect to. th driving disc I9.

The actuation of the ratchet shield is controlled automatically by the travel of a box blank through the machine for effecting a tie stitch at the end of the seam of that blank and at the beginning of the. seam of the next succeeding blank. This mechanism includes a vertically movable tie stitch trip or gauge I09 mounted in an opening in. the table I2 and in the path of the box blanks. This trip I09 has its lower end rigidly secured to a horizontal bar III). The hori zontal bar H0 is pivotally mounted on parallel links III. One of the links III is pivoted on a pin I'IZ carried by the supplemental frame 6d. The other link I I! is secured to a shaft I I3 which in turn is. journaled in a bearing in the supplemental: main frame 60'. Rigidly secured to the shaft H3 is a downwardly extending arm H4. The lower or free end of the depending crank I I4 is connected by a pitrnan II5 to the free end of a second depending crank I55. The crank H0 is secured to a shaft I I! journaled in a bearing in the bracket 55. Secured to the shaft H? and extending at an inclined angle and upwardly with respect thereto is a crank H3. The upper or free end of the crank H s is pivotaily connected as shown at H5 toa link I21 The link IE6 is provided with a longitudinally extending slot IZI. The slot I2I of the link I20 embraces a end of the bar 98.

pin I22 of a shield locking plate I23. The shield locking plate I23 is journaled upon a reduced diameter portion I24 of a hub .01 collar I25 which embraces the shaft 33. The free end of the shield locking plate I23 is provided with a semicircular locking notch I26 which is adapted to engage a pin I21 which in turn is secured to the shield bar 98 and projects laterally on both sides thereof, as clearly shown in Fig. 6 of the drawings. The shields I04 and I together with their supporting or reciprocating bar 98 are held in their uppermost position by a spring I28 which has its upper end as shown at I29 connected to the bearing bracket 95 and its lower end as shown at I30 connected to a pin I3I secured to the lower The tie stitch trip is raised to its normal elevated position in the path of the oncoming box blank by means of a spring I32 which has its lower end connected to the free end of the crank I I4 and its upper end connected as shown at I33 to the bracket 95.. Pivotally connected as shown at I34 to the bracket 95 is a bell-crank member I35. This bell crank member I35 has a downwardly curved and offset arm as shown at I36 and the lower or freeend of this arm as shown at I31 moves in the'path of and is adapted to engage one side of the pin I21 carried by the shield bar 98. The bell-crank I35 is provided with an upwardly extending arm as shown at I 38. Journaled in the upper end of the arm I38 is aroller I39. The roller I39 is located in the path of and is adapted to be engaged by a cam I40 formed on the periphery of the cam plate 80 for controlling the tie stitch ing mechanism in the manner hereinafterdescribed. Formed integrally with the bell-crank I is a horizontally projecting arm I4I which 7 has its free end connected to a spring I42. This spring normally actuates the bell crank in a direction so as to press the. roller I39 against the periphery of the cam 80. Locatedon and projecting through the tabletop I2 and in the path of the incoming box blanks is a clutch throw-in trip or gauge I4I which is provided with conventional operative connections for controlling-the clutchto connect the same with the main drive shaft'I3. This'type of operative trip and its connections are conventional similar'in function and operation to that shown in the FrankE. Lawrence Patent No. 1,708,274, granted April 9, 1929 on Stitching machine and it is therefore thought that a detailed description of the same is unnecessary. It is quite obvious that a manually operated foot treadle may be employed in substitution for this trip gauge if dei sirable. Y

, The operation of our improved automatic tie stitcher is as follows:

The operator grasps abox blank, places it upon the table I2 and pushes it between guides towardsthe stitching mechanism. As the blank 7 moves over the table it depresses trip members I09 and in that order. A forward edge of the blank then passes over the stitching anvil into engagement with tripmember I4I'. At that time the parts are in the condition illustrated inFigs.5and7..

Before the insertion of pin I22. The'depression of the trip I09 moves 'Before the trip member 55 was depressed: the

latch plate I0 was. positively held out of latching position by the pin and slot connection I2, "II. The'eifect of the depression of the trip 55 'is merely to move slotted link 68 toward the right so as to leave latch plate 70 free to swing down into latching position. It remains momentarily in the position illustrated however, being held there by roller I4 on rocker arm 5!.

Now when the work is caused to push against vertical position in which it looks the arm 5!.

down. The depression of arm 5! turns shaft 43 anticlockwise, which throws feed rollers 46 down to press the work against the lower feed rollers 30. As the shaft .43 turns in themanner stated it also swings the arm 54 downin-to; position t hold the main clutch in engagement.

" During the time the first'stitch is being driven the pitmanSS moves from the broken line position of Fig. 5 to the full line position thereof. Then as the shaft I3 turns through the second half of its first revolution the pawl 94 rides up on its first working stroke, but being held out of engagement with the ratchet wheel teeth by 'the guard I02, I04 no rotation of shaft 33 occurs until thepawl rides oif the guard extension I04. Theremaining portion of the working stroke is then effectiveto impart a short'feed movement to the shaft 33 and thence to' the feed rollers 46, 30. The work is therefore advanced through a short space, bringing it ,into'position for the' second stitch. a a

The second stitch is taken during the idling or return stroke of pawl 94. During this'return stroke also the cam plate H50 on disk'80 swings bell crank lever I35 clockwise, and the free end I31 of this lever forces pin I21 on plate 98 downward, moving pawl guard I02, m4 downward and to the'left out of the way of pawl 94. When the pin I21 reaches its lowermost position the latch T plate I23 swings down by gravity,'causing the notch I 26 toiengage the pin I21 andihold it in its lowered position; The pawl 94 is then free to engage the teeth of the ratchet wheel throughout its working stroke, and the blank is ad? vanced a full step thereafter in each feed movement until the latch plate I23 is withdrawn automatically under the control of the" work itself, as W111 presently appear.

1 The driving of stitches and the intermittent action of the feed rollers 30,46 alternate, thereby forming a seam of evenly spaced stitches, thatis beginning with the second stitch driven. During this time bell crank I35 swings back and forth without effect. I 1

Now, when the rear end of the work clears the trip I09, spring I32 acts-through link us and 1 lever I I6, IIStO raise slotted link I 20 and, exert an upward pull upon pin I22. Then while the roller I39is ridingup'on the cam I '40, momentary I ily relieving the parts'from the action of'spring the parts to the position of Fig. 5 without any immediate eifect upon the pawl guard I02, I04."

I28, the link I20 lifts the pin I22 and swings thelatch plate, I23 upwardly to'the position'illustrated. Then, as soon as the roller I39 rides.

down off the cam 140. spring I28 acts to move the pawl guard I02, I04 upwardly to the right to the position shown in Fig. 5. The next feed stroke will therefore be a short one, bringing the work into position for the final tie stitch.

Shortly after the rear end of the work clears the trip I09 it also clears the trip 55, which results in swinging the latch plate 10 backward away from the roller 14. Then, as the last stitch is being driven, the high part of the cam 53 moves out of engagement with follower 52 and the rocker arm 5| is permitted to swing up under the influence of spring 5|. Thereby the shaft 43 is turned clockwise through a small angle, withdrawing arm 54 to cause disengagement of the main clutch, separating feed rollers 30 and 46 and swinging rollers 49 down to press the blank against the constantly rotating delivery rollers 24. The finished blank is thereby ejected from the machine.

It will be observed that when the tail end of the blank clears the trip I09 the ratchet mechanism is automatically set for a short feed, and that it remains so set until after the first feed movement has been transmitted to the blank next to be inserted in the machine. The movement of the second blank into the machine does not cause the first short feed movement. On the contrary it sets in motion means for disabling the shortfeed after the second stitch has been taken. Each piece of work therefore as it enters the machine and depresses the trip I09 has a controlling action to cause a shift at the proper time from short feed to regular feed, and as it clears the trip I09 it has a controlling action to shift from regular feed to short feed.

As previously stated provision is made for varying the spacing between regular stitches by shifting the effective crank arm for pitman 88, and varying the length of the short strokes or tie stitch strokes by adjustment of the pawl guard extension I04. If it should be desired to eliminate tie stitches at the ends of the seam, this can be accomplished by merely disabling the trip I09 and its associated parts, that is by removing the trip or the spring I32.

While in the above specification we have described one embodiment which our invention may assume in practice, it will of course be understood that the same is capable of modification and that modification may be made without departing from the spirit and scope of the invention as expressed in the following claims.

What we claim as our invention and desire to secure by Letters Patent is:

1. The combination with a wire stitching machine, a main drive shaft mounted on said frame, a stitching mechanism mounted on said frame and driven by said shaft for inserting staples in box blanks passing thereunder, box blank feeding mechanism including intermittently driven feed rolls mounted on said frame, a ratchet wheel and pawl mechanism driven by said shaft for actuating said feed rolls and advancing said box blanks in a step by step movement, and means actuated by said box blanks for varying the intermittent movement of said feed rolls.

2. The combination with a wire stitching machine, a main drive shaft mounted on said frame, a stitching mechanism mounted on said frame and driven by said shaft for inserting staples in box blanks passing thereunder, box blank feeding mechanism including intermittently driven feed rolls mounted on said frame, a ratchet wheel and pawl mechanism driven by said shaft for actuating said feed rolls and advancing said box blanks in a step by step movement, means actuated by said box blanks for controlling the intermittent movement of said feed rolls, and means for adjusting said last named means for varying said intermittent movement.

3. The combination with a wire stitching machine, a main drive shaft mounted on said frame, a stitching mechanism mounted on said frame and driven by said shaft for inserting staples in box blanks passing thereunder, box blankfeeding mechanism including intermittently driven feed rolls mounted on said frame, a ratchet wheel and pawl mechanism driven by said shaft for actuating said feed rolls and advancing said box blanks in a step by step movement, and a movable member controlled by said box blank for holding said pawl out of engagement with said ratchet wheel to vary the intermittent movement of said feed rolls.

4. The combination with a wire stitching machine, a main drive shaft mounted on said frame, a stitching mechanism mounted on said frame and driven by said shaft for inserting staples in box blanks passing thereunder, box blank feeding mechanism including intermittently driven feed rolls mounted on said frame, a ratchet wheel and pawl mechanism driven by said shaft for actuating said feed rolls and advancing said box blanks in a step by step movement, and a shield of adjustable length positioned adjacent said ratchet wheel and controlled by said box blank, said shield being adapted to engage said pawl for reducing the movement of said feed rolls.

5. In a machine for stitching a seam, stitching mechanism operating at regularly recurrent intervals, intermittently acting feeding means tending to move the work forward a predetermined distance between successive stitches, means tending to shorten the stroke of the feeding means, latch means for holding said stroke shortening means out of operative position, and means under control of the work for disabling said latch means.

6. In a machine for stitching a seam, stitching mechanism operating at regularly recurrent intervals, intermittently acting feeding means tending to move the work forward a predetermined distance between successive stitches, means tending to shorten the stroke of the feeding means, latch means for holding said stroke shortening means out of operative position, and means under control of the work for causing said latch means to move to operative position after the first two stitches of the seam are driven and for withdrawing said latch means after the next to last stitch is driven.

7. In a machine for stitching a seam, stitching mechanism operating at regularly recurrent intervals, intermittently acting feeding means tending to advance the work a predetermined distance between successive stitches, means for shortening the stroke of the feeding means, means functioning once for each stitch driven tending to move said stroke shortening means out of operative position, latch means for holding said stroke shortening means out of operative position, and means under control of the work for setting said latch means after the first feed movement is completed and withdrawing said latch means prior to the last feed movement.

WALTER R. PABICH. HERBERT. 'I'EILFORS. 

